Hichem Ben Jannet and Zine Mighri*

Abstract: The flower oil of Ridolfia segetum (L.) Moris of Tunisian origin was analyzed by GC and GC/MS. The main constituents of the oil were myristicin and dillapiole, the amounts of which varied depending upon the length of time the flowers were hydrodistilled. The contents of myristicin and dillapiole varied from 13.1–31.5% and 29.5–85.4%, respectively. Oil samples (fractions) were taken every 10 min from 10 to 150 min. Each fraction was screened against three Gram-positive and three Gram-negative bacteria. It was found that the antibacterial activity of the fractions was directly related to their proportions of monoterpenols and phenolic derivatives.

Ridolfia segetum (L.) Moris (Apiaceae) is a widespread plant throughout Tunisia, in the Mediterranean basin and the Canaries where it grows as a weed in the fields of cereals and on badly drained land (1). The essential oils of the different organs of this plant have been the subject of several studies (2–5). Recently, the results of some of these studies showed that the flower oil of R. segetum collected in the Holy Land and the Sinai (4) was dominated by α-phellandrene (44.13–48.87%), piperitenone oxide (8.32–17.98%) and terpinolene (11.8–16.26%). Myristicin and dillapiole were among the minor components representing 0.02–0.52% and 2.62–3.33%, respectively. The flower oil of plants growing in Andulicia province (Spain) (5) was found to contain α-phellandrene (44.5–54.7%), terpinolene (20.1–27.6%) and (Z)-β-ocimene (9.8–10.6%) as major components; myristicin and dillapiole were not detected.